#import bevy_sprite::{mesh2d_functions::{get_world_from_local, mesh2d_position_local_to_clip}}
#import bevy_fast_light::occluder::types::{Vertex, VertexOutput}
// NOTE: `Rgba8Unorm` is 8 bits per channel. This lets us distinguish between 256 colors.
// Therefore `MAX_Z` can't be too high. `Rgba8Unorm` is apparently one of the best
// supported texture formats and I don't necessarily need more precision.
const MAX_Z: f32 = 32.;
@vertex
fn vertex(vertex: Vertex) -> VertexOutput {
let world_from_local = get_world_from_local(vertex.instance_index);
let clip_position = mesh2d_position_local_to_clip(world_from_local, vec4<f32>(vertex.position, 1.0));
let mesh_z = world_from_local[3].z;
return VertexOutput(
clip_position,
saturate(mesh_z / MAX_Z),
);
}
@fragment
fn fragment(in: VertexOutput) -> @location(0) vec4<f32> {
return vec4<f32>(0., 1., in.normalized_z, 1.);
}